Filtration device for a waste water treatment system

ABSTRACT

A filter and housing ( 10 ) for waste water treatment includes a housing ( 10 ) having a plurality of coaxially mounted vertically extending sections adaptable to receive a filter cartridge therein. An upper section ( 12 ) is provided with an outlet consisting of at least two coaxially aligned rings ( 22 ) of preselected diameters wherein the thickness of the rings and the spacing between the rings is sufficient to receive waste water treatment outlets of different diameters. The filter cartridge is comprised of a stacked arrangement of a plurality of disc-dam units ( 32 ) wherein each disc-dam unit ( 32 ) is provided with a serpentine configured first dam ( 46 ), the first dam extending upwardly from an upper surface of the disc-dam unit, the first dam having terminating ends spaced at outer terminating edges ( 34   a   , 34   b ) of the disc dam unit to define a cord segment therebetween. The terminating ends are connected by a second dam ( 46 ) having a height less than the first dam. The serpentine configured first dam divides the disc-dam unit into an upstream side along the outer periphery and a downstream side along the inner periphery. Slots are positioned within the serpentine configured dam on the upstream side thereby providing flow communication with underlying disc-dam units. The top of the first dam is of a preselected height so as to provide a preselected spacing between the top of the first dam and the under surface of an overlying disc-dam unit.

This application is a 371 of PCT/US01/11186 filed Apr. 5, 2001 which isa Continuation-in-part of non-provisional application Ser. No.09/544,200 filed Apr. 6, 2000 now U.S. Pat. No. 6,306,299.

TECHNICAL FIELD

The present invention relates to a filter and filter housing for use ina waste water treatment system and more particularly relates to asectionalized filter housing having capability of receiving filtercartridges of various lengths and is adaptable for connecting to watertreatment tank outlet pipes of varying diameters.

BACKGROUND OF THE INVENTION

In the treatment of waste water, particularly in septic tanks, it iscommon to install filters to remove particulates being discharged fromthe tank which are generally undigested solids so that the dischargingeffluent is a relatively colorless and harmless liquid. There have beena number of filter units designed over the years for the removal ofthese undigested solids from the waste water prior to discharge from aseptic tank or the like. For example, U.S. Pat. Nos. 2,900,084;3,332,552; and, 4,710,295 to Robert Zabel teach a waste water treatmentfiltration system which includes a plurality of disc-dam units disposedin a stack, vertically spaced, in a super-imposed relationship such thatthe bottom of each overlying disc-dam unit cooperates with the upperedges of each underlying unit to form a horizontally elongatedvertically narrow outlet slots. The stack of disc-dam units are mountedin a cylindrical housing with several slots located above and severalslots located below the liquid operating level in a waste water tank. Inoperation, the digested waste water is received through a bottom openingof the housing and the discharging clarified effluent flows through asidewall outlet which is in flow communication with an outlet from thewaste water tank. However, it has been found that septic tanks or wastewater treatment tanks come in different sizes and capacities and alsothe outlet discharge from the waste water tank is not of a standardsize. Thus, for residential and commercial applications it is difficultto provide a filter housing unit of varying filtration capacities andwith discharge outlets adaptable to mate with the various sizes ofoutlet discharge pipes or conduits from the waste water treatment tank.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a filter housing fora waste water treatment tank that includes a plurality of verticallyextending interchangeable sections which allows for the design of afilter housing providing for a filtration system of different filteringcapacities.

It is another object of the present invention to provide a filterhousing have an outlet which is adaptable for mating with waste watertreatment tank outlets of different sizes.

It is a further object of the present invention to provide a filterhousing which is relatively inexpensive and easy to install.

It is even a further object of the present invention to provide a filtercartridge of disc-dam filter units in a filter housing that reducesturbulence during the upflow of waste water in the cartridge.

It is also an object of the present invention to provide a filtercartridge of disc-dam filter units wherein the discs have a diameter ofless than ⅛″ of the inside diameter of the filter housing.

More particularly, the present invention provides a filter and a housingfor a waste water treatment system wherein the housing includes at leastan upper section with an outlet for flow communication with a wastewater treatment tank discharge outlet and a lower section with an openbottom to receive upward flow therethrough. The upper section is mountedabove the lower section and there may be a plurality of middle sectionsmounted between the upper section and the lower section to accommodatefilter cartridges of various lengths. Each of the sections of thehousing include means to receive a plurality of disc-dam units therein.The plurality of disc-dam units in a stack arrangement define the filtercartridge with a longitudinally extending axis. Each of the disc-damunits is of a generally circular-shaped disc having an outer terminatingedge, the base portion of each unit having a planar under surface and anupper surface with a first dam of serpentine configuration having afirst and second terminating end. The dam which extends upwards from theupper surface of the base portion terminates in a dam top whereby apreselected distance is defined between the dam top and the undersurface of an overlying disc. The first end and the second end of thedam define a cord segment therebetween, the dam dividing the baseportion into an upstream and downstream side, the upstream side beingalong an outer periphery of the base portion and the downstream sidebeing along an inner periphery of the base portion. The cord segmentprovides a cut out which extends from a second dam which connects thefirst and second ends of the outer terminating edge of the first damwherein the second dam has a height less than the height of the firstdam. Moreover, each of the discs are provided with a plurality ofupstream openings in the upstream side of the base portion which are inflow communication with an adjacent underlying disc-dam unit. The flowthrough openings are generally positioned within the serpentineconfigured dam. The cut-outs of each disc are aligned to form an outletflow chamber which is in flow communication with an outlet waste watertreatment tank discharge outlet.

The lower section of the housing is provided with an inwardly extendingsealing edge positioned for alignment with the disc-dam unit cut outs.The sealing edge is in contacting relation with the lowermost disc-damunit wherein the sealing edge covers the cut out of the lowermostdisc-dam unit thereby sealing the bottom of the outlet flow chamber fromthe incoming waste water to be filtered.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the invention will be had upon reference tothe following description in conjunction with the accompanying drawingsin which like numerals refer to like parts throughout the several viewsand wherein:

FIG. 1 is a perspective view, with selected portions shown exploded, ofa preferred filter and housing of the present invention;

FIG. 2A is a perspective view of one preferred disc-dam unit of thepresent invention;

FIG. 2B is a perspective view of another disc-dam unit of the presentinvention;

FIG. 2C is a perspective view of a lid for the filter cartridge of thepresent invention;

FIG. 3 is a side elevational view, in section, of the arrangement shownin FIG. 1 in assembled form;

FIG. 4A is an enlarged segmental view showing a method of operation ofthe filter assembly shown in FIG. 1;

FIG. 4B is an enlarged segmental view of the orientation of the discs ofthe present invention received within the lower section of the housing,as shown in an assembled unit of FIG. 1;

FIG. 5A is a perspective view of a lower section of the filter housingof FIG. 1;

FIG. 5B is a perspective view of a middle section of the filter housingof FIG. 1 with selected portions shown in phantom lines;

FIG. 5C is a perspective view of an upper section of the filter housingof FIG. 1;

FIG. 6 is a view of the arrangement of the filter housing assembly shownin FIG. 1 in a waste water treatment tank;

FIG. 7 is a perspective view of another embodiment for a disc-dam unitof the present invention.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring to FIG. 1, which is an exploded perspective view of onepreferred embodiment of the present invention, a filter housing 10includes a plurality of sections mounted one on top of the other. Asshown, the filter housing 10 is provided with an upper section 12mounted above and onto a middle section 14 which, in turn, is mountedabove and onto a lower section 16. Each of the sections are of the samediameter and are made of any suitable material, such as a thermo-plasticmaterial, which is well known in the art. An outlet discharge isprovided on the upper section and is generally comprised of a pluralityof rings, such as rings 20 and 22, of a preselected size and thicknessso that the outlet discharge from the upper section 12 can receive in amale or female arrangement a plurality of waste treatment dischargeoutlets of different diameters. Even though two rings 20 and 22 areshown, it is realized that additional rings may be provided at theoutlet from the upper section 12 to accommodate even a larger number ofwaste water treatment outlets.

Within the filter housing sections 12, 14, 16, a plurality of disc-damunits 32 are in a vertically spaced arrangement, as best shown in FIG.3. A filter cartridge is comprised of a plurality of filter discs ordisc-dam units 32 of generally circular cross section with a cut outcord section which is defined by a dam 46 which connects withterminating edges 34 a and 34 b of a serpentine configured dam 36 andthe inner surface of the sections of the housing, such as upper section12 as shown in FIG. 1. Each disc-dam unit is in parallel with overlyingand underlying discs 32 with interlocking connectors 50 wherein theconnectors 50 are of preselected configuration to provide a spacebetween the dam top 44, and the under surface 42 of an overlying disc32, as best shown in FIG. 3. The disc 32 is generally made of a suitablematerial, such as a thermoplastic material. Also, discs 32 have adiameter as close as possible to the inside diameter of the housingsections 12, 14, 16 as practical. The discs 32 diameter are generallywithin ⅛″ of the inside diameter of housing sections 12, 14, 16 toprevent upflow of solids along the outer periphery of the filtercartridge.

As shown in FIG. 2A, a disc-dam unit 32 comprises an elongated over-flowdam 36 which extends from one of the edges identified as 34 a or 34 b tothe other terminating edge 34 a or 34 b in a serpentine or sinuous pathon the upper surface 40 of the disc 32. The dam 36 extends verticallyupward a preselected distance and in a stacked arrangement defines aspacing between the top 44 of the dam 36 and the under surface 42 of theoverlying disc 32. On one side of the dam 36 is an upstream portionwhich receives upwardly flowing non-filtered material through elongatedslots 38 which are generally located within the curved portion of thesinuous path of the dam 36. Positioning the inlet slots 38 in the curvedportion of the sinuous path provides an upwardly flowing flow path thatis not subjected to turbulence as it flows vertically and over the top44 of the dam 36 and into the downstream side which is defined by theinner periphery of the sinuous path of the dam 36. The outer peripheryof the disc 32 and the outer surface of the dam 36 define the upstreamportion. The serpentine configured dam 36 terminates with a terminatingedge 34 a at one end and with a terminating edge 34 b at an opposed end.The terminating edges 34 a and 34 b are connected by a second or outletdam 46 wherein the outlet dam is of a height less than the height of theserpentine configured dam 36. Thus, the flow of filtered fluid from thedownstream side or inner portion of the disc overflows the dam 46 andinto the outlet chamber 28 which is defined by the stacked arrangementof the discs 32 and the dam 46 terminating edges 34 a and 34 b insealing relation with seal members 24 a, 24 b, 24 c, as shown in FIGS.5A, 5B and 5C. This arrangement defines the outlet chamber 28 forreceiving the filtered waste water from the filter cartridge. Thechamber 28 is in flow communication with the outlet 19 from the wastewater treatment tank 19 (FIG. 6). Centrally located in each of the discsis an opening 48 to receive a support pipe 60 (FIG. 3) therethrough.

The discs 32 are also provided with notches 52 for engaging with lobes54 a, 54 b, and 54 c, of the filter sections 12, 14 and 16 (FIGS. 5A, 5Band 5C). The lobes 54 a, 54 b, and 54 c, and the pipe 60 on which thedisc-dam units 32 are mounted, in alignment with the interlockingconnectors 50, provide for an easy assembly in stable relationshipbetween the plurality of the disc-dams units 32 making up the filtercartridge in a use condition.

FIG. 2B shows a modification of the disc-dam unit 32 wherein thedisc-dam unit in FIG. 2B is identified by the numeral 132 and the onlydifference is the cut out segment 134. In particular, disc-dam unit 132is generally positioned in the upper portion of the upper section 12 forreceipt of a level alarm, level indicating device, or the like, whichmay be placed within the incoming discharge waste water into the filtercartridge. When a level indicator, level control, level alarm, or thelike, is utilized, the top plate, as shown in FIG. 2C, is utilized asthe top disc of a filter cartridge. This disc, identified by numeral232, is provided with a planar surface 240 with an opening 248 thereinto receive the pipe 60 therethrough. Notches 252 are provided forengagement with the lobes 54 c, particularly in the upper section 12.Connectors 250 are also provided for alignment and inner connecting withthe disc 232 and an underlying disc 132. Moreover, cut-outs 234 a and234 b are provided for alignment with terminating edges 34 a and 34 b ofthe discs 32 and 132 and are received by the sealing members 24 c in theupper filter housing section 12. Cut-outs 236 and 238 are also providedin case of an overflow so that the disc 232 does not have an overflow ofwaste water in case the liquid level exceeds the top of the filtercartridge.

Upwardly extending coupling 254 is provided to receive the levelcontrol, level alarm, level indicating means and the like. The coupling254 is in alignment with the cut-out 134 in the disc 132.

FIGS. 5A, 5B and 5C show the details of the three different sectionswhich make up the housing of the filter housing 10. Each of the housingsections 12, 14 and 16 have means to connect to one another in astacking arrangement. In a preferred embodiment, at least an uppersection 12 is mounted to a lower section 16. For units which requirefilter cartridges longer than the filter cartridge which can be arrangedin a spaced stacked arrangement in the two sections 12 and 16, middlefilter housing sections 14 are provided; and, any number of sections 14may be added to the stacking arrangement and is only defined by thevertical height of the filter cartridge as desired by the user.

In FIG. 5A, the lower section 16 is provided with inwardly extendingseal 17 which, as shown in FIG. 4B, receives the second dam 46 thereonto prevent the flow or the intermingling of filtered effluent in thechamber 28 with the incoming waste water flowing upwards through theopening 119. The lower section 16 is provided with lobes 54 c which arefor alignment with lobes 54 b in lower section 14 and lobes 54 a in theupper section 12. The upper portion of the lower section 16 is providedwith an inwardly extending step 16 b which receives the lowerterminating edge 14 a of the middle section 14 or the lower terminatingedge 12 a of the upper section 12. The lower terminating edges 12 a and14 a are of a reduced diameter from the diameter of the exposed outersurface of the remainder of housing portions 12 and 14, respectively.Moreover, the vertical height of the lower terminating edges 12 a and 14a are the same distance as the distance of the upper terminating edge 16a from section 16 from step 16 d. And, in a stacked arrangement theoutside or exposed outer surface of the diameter of the housing is ofthe same diameter from the upper section to the lower section.

As shown in FIG. 5B, the middle section is provided with lobes 54 bwhich are for alignment with the lobes 54 c and 54 a and the sealmembers 24 b which extend vertically along the inner surface of thecylindrical housing section. As shown in the cut-out, middle housingsection 14 is provided with a step 14 b which is a preselected distancefrom the terminating edge 14 c to receive the lower terminating edge 14a of a middle filter housing section 14 or the lower terminating edge 12a of an upper housing section 12.

As shown in FIG. 5C, an upper section 12 is provided with the outlet 18which is comprised of a plurality of rings 20 and 22 to attach to awaste water treatment tank outlet 14. Upper section 12 is also providedwith lobes 54 a for alignment with lobes 54 b and 54 c and engagementwith the cut-outs 52 in the discs 32, 132. Sealing members 24 a are alsoprovided for engagement with the terminating edges 34 a and b of thedisc 32.

An alternative disc filter element 332 is depicted in FIG. 7. As can beseen therein, first filtering dam 36 extends upward from base portion orplanar surface 340. First filtering dam 36 is again of serpentineconstruction. Flow through apertures 38 are formed through base portion340 and are formed between the serpentine curvatures of the first dam.The serpentine curvatures extend the length of the first dam 36 betweenfirst end 34 a and second end 34 b.

Second dam or weir 346 is similarly provided extending between the firstand second end 34 a, 34 b of the first dam. The first dam 36 extendsbetween the flow through apertures 38 and the second dam 346. The seconddam 346 is provided in order to reduce the flow rate of the waterpassing through the filter element 332 which is stacked in a pluralitywithin the filter housing. Fluid passing through the disc-dam filterelement 332 first is filtered through apertures 38, causing particulatematerial to sluff downward through the vertical column defined by theapertures 38 and the plurality of units stacked together, as mentionedabove. A plurality of vertical notches 345 are formed in the second damin order to allow fluid therein to drain appropriately into chamber 28and outlet discharge 19 depicted in the other Figures. Notches 345ensure that no fluid remains undrained in the central portion of basesection 340 after removal of the stacked filter unit. Notches 345 areapproximately {fraction (5/32)} inch in width in order to properlyfilter retain larger particles on base portion 340. Notches 345 act toallow water to flow over planar base portion 340 at a slower rate thanif the weir or second dam 346 were not present. Further, the slower flowrate causes material suspended in the fluid to separate and come to reston the base portion 340. Each of the filter elements 332 are verticallystackable upon one another by the interlocking connectors 50 whichseparate each of the base portions 340 and top edge 44 of first dam by aslight gap to allow filtered fluid therethrough.

By placement of the notches 345 in second dam 346, fluid contained ortrapped therein will drain appropriately. This will be particularly thecase with the filter sections are removed from the housing. Upwardlifting of the stacked filter sections causes the fluid to drain fromthe individual disc filter element 332 such that removal of the stackedfilter elements will not also remove corresponding amounts of fluid fromthe filter housing. Additionally, as depicted in FIG. 7, cylindricalbore support member 347 is provided to extend upwardly and downwardlyfrom the base portion 340 in order to provide an additional support areafor each filter disc-dam unit 332 and receive support pipe 60. Thus, theunits have four support points, each of the three interlockingconnectors 50 and the bore support member 347.

In operation, as shown in FIGS. 3, 4A, 4B and 6, waste water enters thewaste water treatment tank 2 through a waste water inlet 8. Tank 2generally includes at least one or more openings therein identified bythe numeral 4 with a cover 6 thereover which provide for entrance to thetank. At least one opening 4 is shown in alignment with a filter housing10 for easy removal of the sections 12, 14, 16 or discs 32 in filterhousing 10. The waste water entering the tank 2 fills until the level 9is reached which is in alignment with the waste water discharge outlet19. The flow of the waste water is up through the lower filter section16 and is discharged through the outlet 18 in the upper section 12. Asthe waste water discharge flows into the filter housing through theopening 119, the waste water, as shown by the arrows, moves upwardlyadjacent to the central portion of the cartridge unit through theslotted openings 38 in the discs 32. The waste water flowing upwardsthrough the slots 38 provides for the settling of the particles, whichflow downwardly through the slots 38, as the rising waste water movesupwardly through the slots 38 and over flows the top edges 44 of thedams 36. Spacing between the top edge 44 and the under surface 42 of anoverlying disc 32 is of a preselected distance, generally less than an⅛″, so that only very small particles have the opportunity to overflowthe top edge 44. Overflowing waste water is filtered at the selectedspacing between the under surface 42 and the top edge of the underlyingdam top 44 so that relatively clean water exits, into the chamber 28 andout through the outlet discharge 19. By arranging the slots 38 in thecurvature of the serpentine configured dam 36 there is little to noturbulence and the turbulence is minimized at the dam top 44 overflow.Also, it has been found that this reduced turbulence promotes “sluffing”at the interior column because of this lack of turbulence created by thewater moving across the upstream surface of the disc as the dynamics ofthe water is flowing in a vertical condition and not in a vertical andhorizontal condition.

The foregoing detailed description is given primarily for clearness ofunderstanding and no unnecessary limitations are to be understoodtherefrom for modifications will become obvious to those skilled in theart upon reading this disclosure and may be made without departing fromthe spirit of the invention and scope of the appended claims.

1. A wastewater treatment filter comprising: a plurality of stackablefilter elements, each of said elements having a base portion having aplurality of flow through apertures formed therethrough; a firstfiltering dam and a second filtering dam; at least one interlockingconnector extending upward from said base portion; wherein said firstdam extends between said flow through apertures and said second dam. 2.The filter of claim 1 wherein each of said filter elements furthercomprises at least one flow through notch formed in said second dam. 3.The filter of claim 1 wherein said first dam extends upwardly from saidbase portion and has a first end and a second end.
 4. The filter ofclaim 3 wherein said second dam extends between said first and saidsecond end of said first dam.
 5. The filter of claim 4 wherein saidfirst dam has a vertical height which is less than the vertical heightof said at least one interlocking connector.
 6. The filter of claim 5wherein said second dam has a vertical height which is less than saidvertical height of said first dam.
 7. The filter of claim 6 wherein saidvertical height of said second dam is about one-half the vertical heightof said first dam.
 8. The filter of claim 4 wherein said base portion isa circular shaped disc.
 9. The filter of claim 3 wherein said first damis a serpentine configured dam.
 10. The filter of claim 9 wherein saidsecond dam extends between said first end and said second end of saidserpentine dam.
 11. The filter of claim 9 wherein said flow throughapertures are each formed between curvatures formed in said first dam.12. The filter of claim 1 further comprising a support bore extendingupward and downward from said base.